The original wire-wound resistors were spirals of fine resistance wire on a mandrel, and in consequence had a high inductance. Some power resistors are still made this way, with a tubular alumina core and a cermet coating on top of the winding.
Most of the early resistors had an axial construction. The cheapest of these, the “carbon composition” type, was made of a cylindrical slug of high-resistance material with metallised end terminations, and often an end-cap soldered to the metallisation
A more sophisticated and later type of resistor was built on a tube of alumina by depositing a thin carbon film or metal film that was “spiralled” to give the appropriate resistor value. Subsequent adaptations of the same principle used a metal oxide or cermet material in the same way.
Resistors can be made on a flat substrate, with a long path length produced in the coating material by patterning into a meander, either by etching or by laser-machining. Materials put onto glass or ceramic substrates and used in this way have included vacuum-deposited nichrome and tantalum nitride thin film, and a range of bonded foils, predominantly aimed at the precision resistor market.
Finally, semiconductor resistors are available, using either the style of resistor embodied within a microcircuit, or else using the silicon as a substrate for a thin film type.
Of all these styles, except for precision resistors, cermet styles of resistive element are now the most common, predominantly in the form of chip resistors, but also in high power variants, often with built-in heat sinks.
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